Surface Acoustic Wave (SAW) Torque Sensing is an emerging technology for automotive, transportation, rail and other similar industries for use in power train and chassis applications. Significant research and development efforts have allowed for mass-production of SAW torque sensors at a cost-effective price. Certain engine, transmission, driveline and chassis processes can often be controlled more precisely using SAW torque technology. Used in appropriate applications, complex control algorithm and system development, test, evaluation and qualification time can often be significantly reduced with real-time torque sensor measurement that can provide feedback for closed-loop control.
Surface Acoustic Wave (SAW) technology enables wireless, battery-less, non-contacting strain measurement often suitable for the measurement of torque, pressure, temperature and other parameters. The SAW propagation mode is characterized by velocities typically 5 orders of magnitude below electro-magnetic waves with amplitudes in the order of nanometers and wavelengths in micrometers. Most energy is confined to within one wavelength of the surface. These characteristics have made SAW devices often ideal for the design of delay lines and filters widely used in radar, TV and the mobile telecommunications industry. SAW devices are typically designed to operate within the frequency range 30 MHz to 3 GHz.
However, during the course of SAW torque sensor testing where the sensor button is attached to either a shaft or a plate, difficulties have occasionally arisen in maintaining the attachment of the sensor button to the device under torque. Adhesives have not been strong enough under some torque conditions and the sensor does not maintain contact.
It would be of advantage in the art if a device could be provided to attach a sensor such as a SAW torque sensor on a shaft or plate that maintains the sensor in contact with the device under any torque situation to which the device is intended to be used.
Yet another advantage would be if a device could be simply manufactured that would attach to a device to be used under torque.
Other advantages will appear hereinafter.